package main

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
)

// parseHookStdin reads a HookEvent from stdin (Claude Code sends JSON on stdin).
func parseHookStdin() HookEvent {
	var event HookEvent
	json.NewDecoder(os.Stdin).Decode(&event)
	return event
}

// runSetup adds vmux hooks to ~/.claude/settings.json (idempotent).
func runSetup() {
	home := os.Getenv("HOME")
	settingsPath := filepath.Join(home, ".claude", "settings.json")

	vmuxBin, err := os.Executable()
	if err != nil {
		vmuxBin = filepath.Join(home, "Code", "vibe", "vmux", "vmux")
	}

	data, err := os.ReadFile(settingsPath)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Cannot read %s: %v\n", settingsPath, err)
		os.Exit(1)
	}

	var settings map[string]interface{}
	if err := json.Unmarshal(data, &settings); err != nil {
		fmt.Fprintf(os.Stderr, "Cannot parse %s: %v\n", settingsPath, err)
		os.Exit(1)
	}

	hooks, _ := settings["hooks"].(map[string]interface{})
	if hooks == nil {
		hooks = make(map[string]interface{})
		settings["hooks"] = hooks
	}

	hookCommand := vmuxBin + " hook"
	vmuxHook := map[string]interface{}{
		"type":    "command",
		"command": hookCommand,
		"timeout": 5,
	}

	events := []string{"Notification", "Stop", "PostToolUse", "PreToolUse"}
	changed := false

	for _, event := range events {
		entries, _ := hooks[event].([]interface{})

		if hasVmuxHook(entries, hookCommand) {
			continue
		}

		entry := map[string]interface{}{
			"hooks": []interface{}{vmuxHook},
		}

		hooks[event] = append(entries, entry)
		changed = true
	}

	if !changed {
		fmt.Println("vmux hooks already configured.")
		return
	}

	out, err := json.MarshalIndent(settings, "", "    ")
	if err != nil {
		fmt.Fprintf(os.Stderr, "Cannot marshal settings: %v\n", err)
		os.Exit(1)
	}

	if err := os.WriteFile(settingsPath, out, 0o644); err != nil {
		fmt.Fprintf(os.Stderr, "Cannot write %s: %v\n", settingsPath, err)
		os.Exit(1)
	}

	fmt.Printf("vmux hooks added to %s for events: %v\n", settingsPath, events)
	fmt.Println("Restart Claude Code sessions for hooks to take effect.")
}

func hasVmuxHook(entries []interface{}, hookCommand string) bool {
	for _, entry := range entries {
		e, _ := entry.(map[string]interface{})
		hookList, _ := e["hooks"].([]interface{})
		for _, h := range hookList {
			hm, _ := h.(map[string]interface{})
			if cmd, _ := hm["command"].(string); cmd == hookCommand {
				return true
			}
		}
	}
	return false
}